High incidence of focal left ventricular wall motion abnormalities and normal coronary arteries in patients with myocardial infarctions presenting to a community hospital.

BACKGROUND: Myocardial infarction with normal coronary arteries (MINCA) is a well-documented syndrome often associated with global left ventricular wall motion abnormalities (LVWMAs). Recent literature has emphasized the occurrence of Takotsubo cardiomyopathy associated with MINCA. What has not been reported is the incidence of MINCA in the general population and the relative frequency of other types of associated LVWMAs. METHODS AND
RESULTS: Data were retrospectively collected on 165 consecutive patients with ST-elevation myocardial infarction (STEMI) and 244 patients with non-ST-elevation myocardial infarction (NSTEMI) who underwent cardiac catheterization at a single institution in Marin County, California. Thirty-two of the 409 (7.8%) patients had MINCA. Of the patients presenting with STEMI, 10.3% had MINCA, and 6.1% of the patients presenting with NSTEMI had MINCA. Females were more likely to present with MINCA than males, both for STEMI (21.6% vs. 5.3%; p < 0.001) and NSTEMI (12.1% vs. 2.6%; p < 0.001). Of the 32 patients who presented with MINCA, 7 (21.9%) females had Takotsubo cardiomyopathy, while 10 (31.3%) patients (9 females, 1 male) had other previously undescribed focal anterior and inferior LVWMAs. A recent stressful event was noted in 50% (47.8% of females, 55.6% of males) of the patients with MINCA.
CONCLUSIONS: An unexpectedly high incidence of MINCA with newly-described focal anterior and inferior LVWMAs as well as Takotsubo cardiomyopathy was observed in our community hospital. This syndrome occurred predominantly in females and was often associated with a recent stressful event. As these results were from a community, rather than a referral hospital, this finding challenges the current thought about the incidence of this syndrome in the general population.